Common imaging findings of invasive mucinous adenocarcinoma (IMA) include consolidation of the lung parenchyma, nodules, and ground-glass changes. However, the IMA imaging findings in the present case included diffuse, patchy and blurry density shadows through both lungs. To the best of the authors' knowledge, this image pattern has rarely been reported. The patient provided his consent and authorized the publication of photographs featuring his likeness. The present study reported a patient was diagnosed with IMA via pathologic and genetic analyses. Following antibiotic treatment, the lesions in both sides became larger. Further examinations were completed and IMA was confirmed by biopsy pathohistological examination. Pathological specimens were negative for almost all driver genes mutations, except KRAS. The patients and family refused further treatment, including chemotherapy, radiotherapy and interventional chemotherapy and the patient was discharged from The First Affiliated Hospital of Chengdu Medical College. The present case report emphasized that IMA should be suspected when imaging studies show diffuse lesions throughout both lungs. When a patient does not respond to treatment, clinicians should consider alternative diagnoses.